The stock market gyrations this year remind us that economic recoveries are fragile. Although the Standard & Poors 500 index jumped 1.7 percent Thursday, it was down 2.2 percent Wednesday; it’s down 4 percent from a year ago.

Also worrisome is Chapman University’s new California Composite Index, which measures manufacturing in the state. It surveyed purchasing managers and found that “the California manufacturing economy is expected to grow at a slower pace in the first quarter of 2016 compared to the fourth quarter of 2015.” It’s the third consecutive quarter of slower growth.

An index number above 50 indicates expansion; below 50 signals contraction. The latest tally is 56.7, down from 61.2 in the second quarter of 2015. Although the CCI still is in growth terriority, the trend line is downward.

The worst-performing component of the composite index was inventories of purchase materials, at only 50.4; next was supplier deliveries, at 51.2. The most positive element was production, at 60.7.

We’re not predicting a recession. Chapman’s own economic forecast, as well as that of Cal State Fullerton, both expect growth in the state this year reaching 3 percent. But caution is in order, especially for California’s long-abused manufacturing sector.

Despite the protests of Gov. Jerry Brown, the worst part of Senate Bill 350, mandating a 50 percent reduction in gasoline use by 2030, was cut out before passage in September. Many of the governor’s fellow Democrats complained that higher gas costs would especially hurt poor people. However, the bill, among other things, still mandates that 50 percent of state electricity must come from renewable sources by 2030, which will drive up costs.

At the time, Gov. Brown gloomily promised, “Over the next three years, you’re going to see a continuous effort to ratchet up the state’s commitment to clean up our air and reduce carbon pollution, thereby setting an example for the rest of the world on how to save us before it’s too late.”

But, especially if a recession hits, more companies may follow the example of CellPoint of Costa Mesa, NanoBlood LLC of Irvine and hundreds of other manufacturing firms in leaving the state.